| 摘要 |
<p>An upper lid (6) forming an upper portion of a casing (2) is formed by a metal (an aluminum alloy or the like) having a high heat radiation performance. The upper lid (6) serves as a heat sink (a heat radiation member) 20 radiating heat generated from electronic components within the casing (2) to an external portion. A plurality of flat plate-shaped heat radiation fins (21) are provided in an upper surface (20a) of the heat sink (20). A groove (22) forming each of the heat radiation fins (21) is open in a side surface (20b) of the heat sink (20) without forming a step.</p> |
